Visual Testing (VT) Practice Exam

What is the theoretical throat dimension for a 10 mm (0.4 in.) leg fillet weld?

1. 5 mm (0.2 in.)

2. 7 mm (0.3 in.)

3. 10 mm (0.4 in.)

4. 13 mm (0.5 in.)

The correct answer is: 7 mm (0.3 in.)

The theoretical throat dimension for a fillet weld is calculated based on the leg size of the weld. The throat dimension represents the shortest distance from the root of the weld (where the two pieces being joined meet) to the face of the weld (the exposed outer surface). For a fillet weld, the throat can be determined using the formula: Throat = 0.707 x leg size. In this case, with a leg size of 10 mm (0.4 in.), the calculation would be as follows: Throat = 0.707 x 10 mm = 7.07 mm This rounds to approximately 7 mm, which is consistent with the choice provided. Therefore, the theoretical throat dimension for a 10 mm leg fillet weld is indeed around 7 mm (0.3 in.), justifying the choice as the correct answer. This understanding is crucial in ensuring welds meet the necessary strength and quality specifications in engineering and construction applications.